U.S. Pat. No. 5,938,323 A1 shows a holder for a light source in the opening of a reflector for a vehicle headlamp, and a retention ring for the arrangement on the reflector is provided, which has a base body and extends in a ring plane. For the fastening of the retention ring on the opening of the reflector, the retention ring has snap-fastening tabs by means of which the retention ring can be snapped on to the opening of the reflector. The snap-fastening tabs protrude vertically from the ring plane of the retention ring and form barbed hooks, so that the snap-fastening tabs can be snap-fastened to the openings of the reflector.
EP 0 900 974 A2 shows a further holder of a light source in the opening of a reflector for vehicle headlamps, and a retention ring is shown, with which the light source is held in the opening of the reflector. The retention ring has a multitude of expandable elements, holding elements and fastening tongues which each do even form undercuts. Herein the retention ring is embodied as a pressed and bent part and the elements and tongues protruding from the ring plane of the retention ring can get entangled when several retention rings are for example provided in a container for the assembly on the reflector.
Particularly in automatic assembly this is a disadvantage impairing the handling of the retention ring or even making it impossible. When a larger number of retention rings is provided in a container, the retention rings can get caught amongst each other with their molded expandable elements, holding elements and/or fastening tongue which makes the automatic gripping of an individual retention ring for automatic assembly impossible. Magazined provision of retention rings is often space- and cost-intensive and should be avoided.
To avoid this problem, know retention rings possess only pressure points, which are formed on to the base body, and with which the light source is retained in the opening of the reflector. Disadvantageously, the dimensions of the base of the light sources have rather large tolerances, and differences in height of the lamp base could lead to the light source hardly being held by the retention ring or not being held at all.